Why is it important to specify the columns in a SELECT statement instead of using SELECT * in PHP?

Specifying the columns in a SELECT statement is important because it improves query performance by only retrieving the necessary data, reducing the amount of data transferred between the database and the application. Using SELECT * can lead to unnecessary data being fetched, which can impact the performance of the application, especially when dealing with large datasets. Additionally, specifying the columns makes the code more readable and maintainable as it clearly defines what data is being retrieved. 

// Specify the columns in the SELECT statement instead of using SELECT *
$query = "SELECT column1, column2, column3 FROM table_name";
$result = mysqli_query($connection, $query);

// Fetch and display the results
while ($row = mysqli_fetch_assoc($result)) {
    echo $row['column1'] . ' - ' . $row['column2'] . ' - ' . $row['column3'] . '<br>';
}

Keywords

SELECT statement columns PHP performance optimization

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